Having looked in more detail at the #SWICG document. That's not the 3-stage process I advocated for at the time, and I agree with you: It will not work. Such top-down formal ceremony just does not fit a grassroots ecosystem.
Generally speaking I don't think #W3C as a standardization body is up to the task of being a good host for the ActivityPub specification. It is a) not organized for our environment, and b) only takes care of the technical aspects. Our social media landscape has a huge social component, and this is wholly underrepresented in our app-centric fediverse, where people are merely "users" and #FOSS culture is the only driving force.
Today I think SWICG should focus on the 'Protocol implementer' stakeholder: How can they offer compliant #ActivityPub protocol implementations.
Then #FEP can focus on the 'Solution developer', relieved from the plumbing: What interoperable designs do they use to serve the needs of participants on the social network.